This billboard campaign targeted a very special audience. trivago was keen on recruiting software engineers, so we got the challenge to come up something original, attention grabbing which also stimulates this very specific audience. With our own developers, we came up with the idea of the code-only billboards. No company name, no contact address, no words, no call to action, only code - the language our target audience speaks the best. We used the trivago fonts and colors for syntax highlighting, that was the only giveaway.

How the campaign works? Easy. The code on the billboard is written in PHP. If you crack the PHP code on the billboard, you get a link to a secret website. You sign up there and get in contact with one of trivago's engineers for an interview.

We placed these billboards in some local cities like Cologne and Düsseldorf. The general public was confused. Local newspapers asked “What’s up with these new posters?” and people on Facebook were puzzled by what the strange code would mean. We even got into Cologne's major newspaper.

Besides creating quite a buzz on the streets of Cologne, it was also a successful recruiting campaign, within the first few days, around 500 people signed up on our secret website, and some of them even got hired.